Using an earplug may cause earwax to be pushed into the middle ear while the earplugs are inserted into the ear canal, which can cause tinnitus and reduce hearing, pain, or bacterial infection. Earwax users should be more careful use of ear plugs, and ear plugs should always be washed with water and mild soap. However, foam-type earbuds are often discarded when they are used up, and they may lose their slow-rebound characteristics after being soaked in water.

In addition, anti-noise earplugs may also be the cause of otitis, because many bacteria multiply even more under warm, humid conditions.

However, using noise-proof earplugs is usually safe, but some potential dangers that may arise from long-term use must be prevented:

When inserted into the earplugs, it causes the pressure in the middle ear to rise and push toward the ear drums to cause pain. This is because the earplugs are inserted too deeply. To avoid this danger, first rub the earplugs carefully and insert them into the pre-set ideal position. When the earplugs are fully inflated, it is best not to push them inwards. Vice versa, when pulling out the earplugs in order to avoid crowded ear drums, earplugs should be slowly unscrewed rather than pull out.